As the image-recording methods in which images are formed on a medium to be recorded (or a recording medium) such as paper on the basis of image data signals, there have been known, for instance, the electrophotogaphy technique, the sublimation-type and melt-type thermal ink-transfer techniques, and the ink jet-recording technique. The electrophotogaphy technique requires the use of a process for forming an electrostatic latent image on a drum made of a light-sensitive material through charging and light-exposure operations and therefore, this technique suffers from various problems. For instance, the technique requires the use of a complicated system and this in turn results in an increase in the production cost. In addition, the device used in the thermal ink-transfer technique is rather cheap, but this technique suffers from problems in that the technique requires the use of an ink ribbon, this in turn leads to an increase in the running cost and the generation of a large amount of waste matter. On the other hand, the ink jet-recording technique uses a cheap device and is a technique in which images are directly formed on a recording medium by discharging ink only on the desired image area. Accordingly, this technique permits the efficient use of the ink and requires a reduced running cost. Furthermore, this technique is less noisy and therefore, it is quite excellent as an image-recording technique.
As an example of such an ink jet recording technique, there has been known a recording technique which makes use of an ink jet-recording ink capable of being cured through the irradiation thereof with radiant rays.
For instance, such an ink jet-recording technique using an ultraviolet ray-curable ink jet-recording ink has attracted special interest lately since this technique may give out a relatively small quantity of bad smells, is excellent in the quick drying ability and permits the recording of images even on a recording medium free of any ink absorbability. There has been proposed, in the following Patent Document 1, a composition comprising a polymerizable compound selected from the group consisting of specific acrylate compounds and a coloring material for the purpose of providing a highly safe ink jet-recording ink, which can record images even on a substrate whose direct recording of images according to the ink jet-recording technique has in general been believed to be considerably difficult, without causing any bleeding, while ensuring high sensitivity and high adhesion to a recording medium and which has only a reduced skin-irritating effect and/or only a slight sensitization.
Patent Document 1: Japanese Un-Examined Patent Publication (hereunder referred to as “J.P. KOKAI”) 2003-192943